In September 2007 cavers of the Ukranian Speleological Association reached a new record depth of 2,191 m (7,188 ft 3 in) in the Krubera Cave in the Arabika Massif, Georgia. Over 2.5 km (8,202 ft) of new cave passages were explored in this 29-day underground expedition.

The greatest depth accurately measured for any bird is 534 m (1,751 ft) by a 29-kg (63-lb 14.4-oz) emperor penguin (Aptenodytes forsteri) at Coulman Island, Ross Sea, Antarctica, and recorded by Professor Gerald Kooyman of the Scripps Institution of Oceanography in November 1993. Kooyman measured almost 16,000 dives from five different birds, the longest of which lasted 15.8 minutes.

The deepest underwater dive by a flying bird is 210 m (690 ft) by a Brünnich’s guillemot or thick-billed murre (Uria lomvia) with a maximum speed of descent of around 2 m (6 ft 6 in) a second. Auks in general are excellent swimmers and recent technology has made tracking the depth of their dives much easier. Devices have shown that murres make up to 20 consecutive dives staying at the surface for less than a minute between each dive. Some murres have recorded dives Continue reading →

The deepest part of the ocean was first pinpointed in 1951 by HM Survey Ship Challenger in the Mariana Trench in the Pacific Ocean. On 23 January 1960 the manned US Navy bathyscaphe Trieste descended to the bottom, and on 24 March 1995 the unmanned Japanese probe Kaiko recorded a depth of 10,911 m (35,797 ft), the most accurately ever measured, when it also reached the bottom.  If Mount Everest was dropped into the Mariana Trench, it would disappear 2,000 metres below the surface.

On 18 December 2009 US scientists announced they had filmed a volcanic eruption more than 1,200 m (3,900 ft) deep in the Pacific Ocean near Samoa. The footage, captured in May 2009 by a robotic submersible, shows molten lava erupting from the West Mata volcano, one of the most active submarine volcanoes in the world.

On 28 November 1996 Blue Water Recoveries Ltd (UK) discovered the wreck of the SS Rio Grande, using side-scanning sonar, at the bottom of the South Atlantic Ocean. On 30 November 1996 the find was confirmed by the company using a remotely-operated vehicle. The wreck, a World War II German blocade runner, lies at a depth of 5,762 m (18,904 ft).

Earth is the densest planet, with an average density of 5.517 times that of water.

Black holes are the remnants of stars that ended their lives as supernovae. They are characterised by a region of space in which gravity is so strong that not even light can escape. The boundary of this region is known as the event horizon and, at the centre of the black hole, is the singularity, where the mass of the dead star is compressed to a single point of zero size and infinite density. It is this singularity that generates the powerful gravitational field of Continue reading →

The wonder plant (Welwitschia mirabilis) of the Namib Desert in Namibia and Angola only produces two leaves, but they are far longer than those of any other species of desert plant, each one growing between 2-4 m long, though they eventually become split, or at least become shredded at their tips, due to the arid desert winds and harsh living conditions experienced in this environment. In contrast, the leaves of other desert plants are usually very small, to prevent water loss via evaporation.

The official FAI distance record for a manned balloon is 40,814 km (25,361 miles) set by Bertrand Piccard (Switzerland) and Brian Jones (UK), who piloted the Breitling Orbiter 3 from 1 to 21 March 1999. For comparison, the length of the Equator is 40,075 km. (24,902 miles). Piccard and Jones’ flight was also the first circumnavigation of the globe, after years of attempts, an indication of the difficulty of the feat.